NREM‐related parasomnias in Machado–Joseph disease: clinical and polysomnographic evaluation

Abstract

SUMMARYSpinocerebellar ataxias (SCA) are autosomal dominant neurodegenerative disorders that affect the cerebellum and its connections, and have a marked clinical and genetic variability. Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3)-MJD/SCA3-is the most common SCA worldwide. MJD/SCA3 is characterized classically by progressive ataxia and variable other motor and non-motor symptoms. Sleep disorders are common, and include rapid eye movement (REM) sleep behaviour disorder (RBD), restless legs syndrome (RLS), insomnia, excessive daytime sleepiness, excessive fragmentary myoclonus and sleep apnea. This study aims to focus upon determining the presence or not of non-REM (NREM)-related parasomnias in MJD/SCA 3, using data from polysomnography (PSG) and clinical evaluation. Forty-seven patients with clinical and genetic diagnosis of MJD/SCA3 and 47 control subjects were evaluated clinically and by polysomnography. MJD/SCA3 patients had a higher frequency of arousals from slow wave sleep (P < 0.001), parasomnia complaints (confusional arousal/ sleep terrors, P = 0.001; RBD, P < 0.001; and nightmares, P < 0.001), REM sleep without atonia (P < 0.001), periodic limb movements of sleep index (PLMSi) (P < 0.001), percentage of N3 sleep (P < 0.001) and percentage of N1 sleep (P < 0.001). These data show that NREMrelated parasomnias must be included in the spectrum of sleep disorders in MJD/SCA3 patients.

Assessment of Sleep Spindle Density among Genetically Positive Spinocerebellar Ataxias Types 1, 2, and 3 Patients

“…They had reported significantly higher frequency of arousals from slow wave sleep to higher parasomnia complaints like confusional arousal/sleep terrors, higher REM sleep without atonia and more periodic limb movements of sleep. They showed that NREM parasomnias are significantly present in SCA3 [16]. However, our study was conducted only to study the SSD, hence Parasomnias could not be evaluated.…”

“…Various symptoms of SCA types 2 and 3 like gait, limb and truncal ataxia, frequent falls, dysarthria, saccadic disturbances and executive dysfunction attribute to the involvement of re-entrant circuits, which need thalamic integrity [9]. Silva et al [16] evaluated 47 genetically proven cases of SCA 3 by polysomnographic studies and compared the results of these studies with those of the controls. They had reported significantly higher frequency of arousals from slow wave sleep to higher parasomnia complaints like confusional arousal/sleep terrors, higher REM sleep without atonia and more periodic limb movements of sleep.…”

The Sleeping Cerebellum

“…Vice versa, patients suffering from primary malfunctions of the cerebellum can show a variety of sleep disorders (for a detailed review, see [11,[69][70][71][72][73]). For example, patients with spinocerebellar ataxias [69,70,74,75], which are characterized by degeneration of the cerebellum and its afferent and efferent connections, can show increased daytime somnolence as well as NREM-and REM-related parasomnias. These data underline that the cerebellum fine-tunes neocortical forms of sleeprelated activity.…”

Sleep disorders in spinocerebellar ataxia type 10

“…Other SCA3 series showed a reduction in REM sleep percentage and an increase in REM sleep latency and REM sleep arousals even in the absence of RBD (Boesch, Frauscher, Brandauer, Wenning, Högl, et al., ; Pedroso, Braga‐Neto, et al., ; Pedroso, França, et al., ; Raggi et al., ). SCA3 patients also have non‐rapid eye movement (NREM)‐related parassonias (Silva et al., ).…”

“…Patients with RBD also experience pathological changes in basal ganglia anatomy, with neuroimaging studies showing reduced striatal dopaminergic activity (Pedroso et al., ). However, sleep disorders in neurodegenerative diseases may be associated with more diffuse structural damage in the central nervous system, more specifically to sleep–wake‐generating cells and their networking (Raggi et al., ; Silva et al., ).…”